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FREQUENCY RESPONSE ANALYSIS IN INTERNAL FLOWS

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Journal of Hydrodynamics 1995年第3期7卷 39-49页

作者： Zhang, Lixiang Tijsseling, A.S. Vardy, A.E. yunnan polytechnic univ Kunming China

Frequency response analysis of the liquid-filled pipeline is an important way to obtain the dynamic behavior of piping systems subjected to internal/external excitations. This study applies Laplace transform to hyperbolic partial differential equations which describes the axial motion taking into account Fluid Structure Interaction (FSI). An effective and convenient method to tackle frequency analysis and to pick up resonance frequencies of the system was developed, four wave modes in the frequency domain being used in combination of solution. The efficiency of this method is well proved with the examples.

关键词： Frequency response Laplace transforms Numerical analysis Pipe flow Water hammer

Alloying Elements in High Speed Steels

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Journal of Iron and Steel Research International 1999年第2期6卷 33-38页

作者： Pan Fusheng Tang Aitao Chen Jian Zhang Jin Ding Peidao Yong Qilong Chongqing university yunnan polytechnic university

Effects of alloying elements,Si,Nb,Ti,W,Mo,V,Al and rare earth metals on the microstructure and properties of high speed steels(HSSs) have been *** attention is paid to effects of Si on the secondary hardening and V on the morphology of eutectic carbides in HSSs.A lot of work has been carried out on the behavior of alloying elements in HSSs in the past decade,and some new types of HSSs containing silicon,aluminum or rare earth metals have been successfully developed in the world.

关键词： high speed steel alloying element microstructure mechanical property

UNIQUENESS FOR THE SOLUTIONS OF ELASTIC THIN PLATES AND SHALLOW SHELLS AS WELL AS THEIR CONTACT PROBLEM WITH HALF SPACE

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Applied Mathematics and Mechanics(English Edition) 2000年第3期21卷 335-340页

作者：范家参 School of Civil Engineering Yunnan Polytechnic University 650051 Kunming P R China

The uniqueness for the solutions mentioned in the subject is proved by using the uniqueness of the solution for the internal boundary problem of Laplace and bi-Laplace equations of the first kind as well as of the sec... 详细信息

关键词： harmonic and bi-harmonic functions uniqueness of solution elastic plates and shallow shells contact problem with the elastic half space

Modified Block Iterative Method for Solving Convex Feasibility Problem, Equilibrium Problems and Variational Inequality Problems

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Acta Mathematica Sinica,English Series 2012年第4期28卷 741-758页

作者： Shi Sheng ZHANG Chi Kin CHAN H.W.JOSEPH LEE College of Statistics and Mathematics Yunnan Uniersity of Finance and Economics Department of Applied Mathematics The Hong Kong Polytechnic University

The purpose of this paper is by using the modified block iterative method to propose an algorithm for finding a common element in the intersection of the set of common fixed points of an infinite family of quasi-C-asymptotically nonexpansive and the set of solutions to an equilibrium problem and the set of solutions to a variational inequality. Under suitable conditions some strong convergence theorems are established in 2-uniformly convex and uniformly smooth Banach spaces. As applications we utilize the results presented in the paper to solving the convex feasibility problem （CFP） and zero point problem of maximal monotone mappings in Banach spaces. The results presented in the paper improve and extend the corresponding results announced by many authors.

关键词： Modified block iterative algorithm quasi-φ-asymptotically nonexpansive mapping quasi-φ-nonexpansive mapping relatively nonexpansive mapping generalized projection

FORCED　OSCILLATIONS　OF　BOUNDARY　VALUE　PROBLEMS　OF　HIGHER　ORDER　FUNCTIONAL　PARTIAL　DIFFERENTIAL　EQUATIONS

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Applied Mathematics and Mechanics(English Edition) 1996年第9期17卷 889-900页

作者：靳明忠董莹李崇孝 Wuhan Automotive polytechnic university Wuhan P. R. China yunnan polytechnic university Kunming P. R. China

In this paper we study the forced oscillations of boundary value problems of a class of higher order functional partial differential *** principal tool is an everaging techniqe which enables one to establish oscillati... 详细信息

关键词： higher order functional partial differential equation boundary value problems forced oscillation

The MADS-box gene RhAGL6 plays a master role in regulating the receptacle malformation in rose at low temperature

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Horticultural Plant Journal 2024年第5期10卷 1214-1229页

作者： Weikun Jing Shuai Zhang Qingcui Zhao Yang Liu Liangjun Zhao Junping Gao Nan Ma Xiaofeng Zhou Yonghong Li School of Food and Drug Shenzhen PolytechnicShenzhen 518055China Department of Ornamental Horticulture College of HorticultureChina Agricultural UniversityBeijing 100193China Postdoctoral Innovation Practice Base Shenzhen PolytechnicShenzhen 518055China Flower Research Institute of yunnan Academy of Agricultural Sciences KunmingYunnan 650205China

Low temperature usually results in the developmental deformity of flower organs,immensely affecting the quality of rose ***,it's largely unknown about the regulatory mechanisms activated by low ***,we used a low temperature-sensitive Rosa hybrida cv.‘Peach Avalanche’to screen a MADS-box gene RhAGL6 via conjoint analysis between RNA sequencing(RNA-seq)and whole-genome bisulfite sequencing(WGBS).Furthermore,we found that low temperature induced the hypermethylation and elevated histone 3 lys-27 trimethylation(H3K27me3)level on the RhAGL6 promoter,leading to decreased RhAGL6 *** addition,RhAGL6 silencing resulted in the formation of abnormal *** also found that the levels of gibberellins(GA3)and abscisic acid(ABA)in the receptacle under low temperature were lower and higher,respectively,than under normal *** activity analysis revealed that GA3 significantly activated RhAGL6 promoter activity,whereas ABA inhibited ***,we propose that RhAGL6 regulates rose receptacle development by integrating epigenetic regulation and phytohormones signaling at low temperature.

关键词： Rosa hybrida Low temperature RhAGL6 Receptacle development DNA methylation H3K27me3 Phytohormone

A coarse-to-fine strategy for the registration of the multi-wavelength high-resolution solar images

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Research in Astronomy and Astrophysics 2020年第7期20卷 117-126页

作者： Rui Wang Zhi Xu School of Electronics and Information Xi’an Polytechnic UniversityXi’an 710048China yunnan Astronomical Observatory Chinese Academy of SciencesKunming 650011China

The registration of multi-wavelength high-resolution solar images is an important task in the research of solar physics. This paper proposed a coarse-to-fine strategy to realize the accurate registration of high-resolution photospheric images and chromospheric images observed by the New Vacuum Solar Telescope(NVST) whose field-of-view is about 2′~ 3′, and the spatial resolution can reach 0.1′′after image reconstruction. In this strategy, the full-disk solar images with relatively lower resolution taken by other space-or ground-based telescopes are taken as transition images, and the Fourier-Merlin transform,Template matching and a local statistical information based algorithm are used in combination. After registration, the geometric transformation between multi-wavelength images of NVST are corrected at the level of sub-arcseconds, including the rotation, scaling and translation relations. Two sets of data observed in active regions(i.e., the NOAA 11982 and the NOAA 12673) are used to illustrate our method step by *** result shows that the registration accuracy can reach less than 1′′. Moreover, this work also has facilitated the combination of high-resolution observations of NVST with the continuum, ultraviolet passbands and magnetic field observations of the Solar Dynamic Observation(SDO), which is highly beneficial to the multi-instrument joint measurement of solar activities.

关键词： instrumentation:detectors methods:observational techniques:image processing Sun:general

Color excesses of type Ia supernovae from the single-degenerate channel model

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Research in Astronomy and Astrophysics 2009年第11期9卷 1259-1269页

作者： Xiang-Cun Meng Xue-Fei Chen Zhan-Wen Han Wu-Ming Yang School of Physics and Chemistry Henan Polytechnic University Jiaozuo 454000 China National Astronomical Observatories/yunnan Observatory Chinese Academy of Sciences Kunming650011 China

The single degenerate model is the most widely accepted progenitor model of type Ia supernovae （SNe Ia）, in which a carbon-oxygen white dwarf （CO WD） accretes hydrogen-rich material from a main sequence or a slightly evolved star （WD＋MS） to increase its mass, and explodes when its mass approaches the Chandrasekhar mass limit. During the mass transfer phase between the two components, an optically thick wind may occur and the material lost as wind may exist as circumstellar material （CSM）. Searching for the CSM around a progenitor star is helpful for discriminating different progenitor models of SNe Ia. In addition, the CSM is a source of color excess. The purpose of this paper is to study the color excess produced from the single-degenerate progenitor model with an optically thick wind, and reproduce the distribution of color excesses of SNe Ia. Meng et al. systemically carded out binary evolution calculations of the WD ＋MS systems for various metallicities and showed the parameters of the systems before Roche lobe overflow and at the moment of supernova explosion in Meng ＆ Yang. With the results of Meng et al., we calculate the color excesses of SNe Ia at maximum light via a simple analytic method. We reproduce the distribution of color excesses of SNe Ia by our binary population synthesis approach if the velocity of the optically thick wind is taken to be an order of magnitude of 10km s^-1. However, if the wind velocity is larger than 100km s^-1, the reproduction is bad.

关键词： stars white dwarfs -- stars supernova general

The structure of weak Pareto solution sets in piecewise linear multiobjective optimization in normed spaces

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Science China Mathematics 2008年第7期51卷 1243-1256页

作者： ZHENG XiYin YANG XiaoQi Department of Mathematics Yunnan UniversityKunming 650091China Department of Applied Mathematics the Hong Kong Polytechnic UniversityHung HumKowloonHong KongChina

In general normed spaces, we consider a multiobjective piecewise linear optimization problem with the ordering cone being convex and having a nonempty interior. We establish that the weak Pareto optimal solution set of such a problem is the union of finitely many polyhedra and that this set is also arcwise connected under the cone convexity assumption of the objective function. Moreover, we provide necessary and sufficient conditions about the existence of weak (sharp) Pareto solutions.

关键词： piecewise linear function weak Pareto solution connectedness normed space 90C29 90C30 90C31